Shared reference for a charging data resource for PDU sessions in communications system

Abstract

An AMF of a communications system responds to receipt of a network attach request message of a UE requesting attachment to a network of the communication system, by sending a charging data request message toward a CHF containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications associated with UE while attached to the network. The AMF receives a response message of the CHF containing a reference for the charging data resource associated with the UE while attached to the network. The AMF responds to receiving a PDU session establishment request message of the UE, by sending a PDU session establishment request message containing the reference for the charging data resource toward a SMF. Related SMF and CHF of the communications system are disclosed.

The invention claimed is: 
     
         1 . A method by an access management function, AMF, of a communications system, the method comprising:
 responsive to receiving a network attach request message of a user equipment, UE, requesting attachment to a network of the communication system, sending, from the AMF, a charging data request message toward a charging function, CHF, containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications associated with UE while attached to the network;   receiving, at the AMF, a response message of the CHF containing a reference for the charging data resource associated with the UE while attached to the network; and   responsive to receiving a protocol data unit, PDU, session establishment request message of the UE, sending, from the AMF, a PDU session establishment request message containing the reference for the charging data resource toward a session management plane function, SMF.   
     
     
         2 . The method of  claim 1 , wherein the reference for the charging data resource is a Uniform Resource Identifier, URI, composed of a string of characters that unambiguously identifies a charging data resource record at the CHF which is used to track charging for network resources used for communications during one or more PDU sessions with the UE. 
     
     
         3 . The method of  claim 1 , further comprising:
 responsive to receiving another PDU session establishment request message of the UE, sending, from the AMF, another PDU session establishment request message containing the reference for the charging data resource toward the SMF.   
     
     
         4 . The method of  claim 3 , wherein the PDU session establishment request message and the another PDU session establishment request message are received while the UE maintains attachment to the network without performing an intervening request to detach from the network. 
     
     
         5 . The method of  claim 1 , further comprising:
 responsive to receiving a network detach request message of the UE requesting detachment from the network, sending, from the AMF, a charging data request message toward the CHF including a notification to terminate use of the reference for the charging data resource.   
     
     
         6 . The method of  claim 5 , wherein the sending of the charging data request message comprises retrieving the reference for the charging data resource from local memory of the AMF or connected memory, using an identifier of the UE as a lookup pointer. 
     
     
         7 . The method of  claim 1 , further comprising:
 forwarding the reference for the charging data resource to a Short Message Service Function, SMSF, or a Network Exposure Function, NEF.   
     
     
         8 . A method by a charging function, CHF, of a communications system, the method comprising:
 responsive to receiving a charging data request message of a user equipment, UE, requesting attachment to a network of the communication system and containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications while the UE is attached to the network, sending a response message containing a reference for the charging data resource toward an access management function, AMF;   responsive to receiving a charging data request message for a protocol data unit, PDU, session requested by the UE, sending a charging data response message; and   tracking charging for network resources used for communications during the PDU session with the UE using the reference for the charging data resource.   
     
     
         9 . The method of  claim 8 , wherein the reference for the charging data resource is a Uniform Resource Identifier, URI, composed of a string of characters that unambiguously identifies a charging data resource record at the CHF which is used to track charging for network resources used for communications during one or more PDU sessions with the UE. 
     
     
         10 . The method of  claim 8 , further comprising:
 responsive to receiving another charging data request message for another PDU session requested by the UE, sending another charging data response message; and   tracking additional charging for additional network resources used for communications during the another PDU session with the UE using the reference for the charging data resource.   
     
     
         11 . The method of  claim 10 , wherein the charging data request for the PDU session and the another charging data request message for the another PDU session are received while the UE maintains attachment to the network without performing an intervening request to detach from the network. 
     
     
         12 . The method of  claim 8 , further comprising:
 embedding the reference for the charging data resource in the charging data response message sent by the CHF responsive to receiving the charging data request for the PDU session requested by the UE.   
     
     
         13 . The method of  claim 8 , further comprising:
 responsive to receiving a charging data request message of the AMF or a session management plane function, SMF, to terminate use of the reference for the charging data resource, closing the charging data resource and sending a charging data response message toward the AMF or the SMF.   
     
     
         14 . The method of  claim 13 , wherein the charging data request message comprises the reference for the charging data resource. 
     
     
         15 . The method of  claim 8 , further comprising:
 responsive to receiving a charging data request message of the AMF or the SMF to terminate use of the reference for the charging data resource, removing or updating database entries of a CHF database associated with the reference for the charging data resource, and sending a message to a billing system node of the communications network that contains billing information generated based on the entries from the CHF database associated with the reference for the charging data resource.   
     
     
         16 . A method by a session management plane function, SMF, of a communications system, the method comprising:
 responsive to receiving a protocol data unit, PDU, session establishment request message related to a user equipment, UE, requesting attachment to a network of the communications system and that contains a reference for a charging data resource associated with the UE while attached to the network, sending toward a charging function, CHF, a charging data request message for the PDU session that contains the reference for the charging data resource and by starting a charging session for the PDU session using the reference; and   responsive to receiving a charging data response message of the CHF, communicating with an access management function, AMF, to establish the PDU session for the UE comprising sending a PDU session establishment message toward the AMF, wherein the reference for the charging data resource is embedded in the PDU session establishment message.   
     
     
         17 . An access management function, AMF, of a communications system comprising:
 at least one processor; and
 at least one memory coupled to the at least one processor and comprising computer readable program code that when executed by the at least one processor causes the at least one processor to perform operations configured to: 
 responsive to receiving a network attach request message of a user equipment, UE, requesting attachment to a network of the communication system, send, from the AMF, a charging data request message toward a charging function, CHF, containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications associated with UE while attached to the network; 
 receive, at the AMF, a response message of the CHF containing a reference for the charging data resource associated with the UE while attached to the network; and 
 responsive to receiving a protocol data unit, PDU, session establishment request message of the UE, send, from the AMF, a PDU session establishment request message containing the reference for the charging data resource toward a session management plane function, SMF. 
   
     
     
         18 . The AMF of  claim 17 , wherein the computer readable program code when executed by the at least one processor further causes the at least one processor to perform operations configured to perform a method by an access management function, AMF, of a communications system, the method comprising:
 responsive to receiving a network attach request message of a user equipment, UE, requesting attachment to a network of the communication system, sending, from the AMF, a charging data request message toward a charging function, CHF, containing a notification for the CHF to keep a charging data resource to track charging for network resources used for communications associated with UE while attached to the network;   receiving, at the AMF, a response message of the CHF containing a reference for the charging data resource associated with the UE while attached to the network;   responsive to receiving a protocol data unit, PDU, session establishment request message of the UE, sending, from the AMF, a PDU session establishment request message containing the reference for the charging data resource toward a session management plane function, SMF,   wherein the reference for the charging data resource is a Uniform Resource Identifier, URI, composed of a string of characters that unambiguously identifies a charging data resource record at the CHF which is used to track charging for network resources used for communications during one or more PDU sessions with the UE.